Chimney structure



Sept. 12, 1944. E. ZIMMERMAN CHIMNEY STRUCTURE Filed Feb. 15, 1943 F Inventor EM/Z Z/MMHiMA/l B W vM preferably made of sheet metal.

Patented Sept.'12, 1944 I CHIMNEY STRUCTURE 7 Emil Zimmerman, Everett, Wash.

Application Februar 15, 1943, Serial No. 475,894

6 Claims.

The chimney structure to which my invention relates is an improvement over that disclosed in my Patent No. 2,269,050, issued Jan. 6, 1942, fora Chimney cap.

The principal object of myv present chimney structureis to increase the draft over that which is afforded by the cap of my above mentioned patent. Additionally the flow of air through the chimney will be less turbulent and less restricted so that the draft conditions are more uniform, as well as being stronger. Furthermore there is less danger of air blowing down the chimney under very unusual wind conditions.

These improved results are obtained by the use of a simplified structure, and one whose appear! ance blends more attractively with the conventional brick chimney. In'addition my present construction is more durable, although less expensive to fabricate.

While the structure illustrated in the drawing is the one which I now prefer, slight modifications in its arrangement. and construction may be permissible, provided that its operation is not impaired and the other objects enumerated above are achieved. 7

Figure 1 is a top perspective view of my chimney showing parts broken away. Figure '2 is a vertical sectional view through the chimney structure illustrating the manner in which it is supported upon a chimney, and Figure 3 is a transverse section through the assembly on the line 3-3 of Figure 2.

While the principle upon which my present chimney'structure operates is in general similar to that of my chimney cap disclosed in Patent No. 2,269,050, thearrangement and proportioning of the parts in my present installation produce a superior performance particularly noticeable in the improvement in draft. While the structure may be incorporated in the chimney C as it is fabricated, I prefer that it be formed as an attachable unit, which, for the most part, may be constructed of concrete or other ceramic material, tobe superimposed upon the chimney. 4

Such a unit, which is shown in the drawing, includes a body I having outside dimensions corresponding to those of the chimney C, and a flue opening at least as large as that of the chimney proper and aligned with it. The upper end of the chimney or auxiliary unit is closed by a cover 2, which preferably can be lifted off for access to the internal parts. Within the body and spaced below the cover is a dished deflector 3, which is This deflector is a hollow frusto-pyramidal pan, the sides of which flare upward from a bottom of substantial area. While the deflector illustrated is rectangurlar it is intended that the term frusto-pyramidal or truncated pyramidal" be understood in its generic sense to embrace any polysided structure including a frusto-conical or truncated conical deflector, which is the special case for apyramid having an infinite number of sides.

The body I is usuallysquare, although it. may

be rectangular or of other shape, and at its upper end includes a notch or aperture 10 in each side.

If the body is circular it should include at least three such apertures, and,.although there may be more than four, a greater number is unnecessary. In any case it is desirable that the chimney or body top be open at all sides. defined by'notches, pillars Hdividing adjacent notches will be formed, one upstanding from each corner of the body I to serve as supports for cover 2. t a

The cover 2 has imperforate partitions 20 projecting' downward from it between each pair of adjacent openings: l0 and extending centrally, diagonally across the upper end of the chimney.

These partitions project downward somewhat be-. low the lower edges of such openings, and extenda short distance into the deflector 3. Preferably these partitions are-cast or molded integral with the cover 2, when fabricated ofconcrete or similar material, and converge toward its "center. The cover may become progressively thicker to-' ward its central portion 2 I to provide surfaces 22.

between the partitions curving inwardly and downwardly from the cover edges. the cover margin projects outward somewhat be- If the openings are Preferably yond the outer surface of the body I, for reasons which will be described hereaften. l r

The dished deflector 3 may besupported in any suitable manner centrally within the body I, but preferably is suspended from the lower edges of openings ID by fingers 3B projecting outward from the center of each side edge of the deflector. These may fit into notches in the body walls forming the lower edges of the openings or be hooked to fit over them. The upper edge of each deflector side is spaced inwardly from the inner surface of the corresponding flue wall to leave a smoke passage between these two elements. As shown best in Figure 2 the partitions 20 not only extend downward below the lower edges of aper-r tures I0, but also project a short distance down into the deflector 3. 1 7

In order to obtain the most efiicientoperation from a structure of this general type the arrangement and proportion of the parts are important,

draft.

and uniform as can be obtained.

of the smokethrough it.

and this is particularly true of the shape, size and location of the deflector withinthe chimney. In particularif the best draft conditions are to be obtained the air flowing laterally through the chimney should be deflected as little as possible during its passage, while still obtaining good Moreover the air flow should be as smooth To provide a smoke passage between the flue walls and the deflector 3. its upper'dimension is.

smaller than the internal width of the chimney, being perhaps 70% of the chimney width so that is allowed on each side of the deflector for.

not more than the width of, the smoke, passage,

a and may, for example, be about 10% of the inter nal. width of the chimney below the lower edge of such opening. This size and disposition of the deflector, inconjunctionwith the projecting margins of the cover, insure that the air flowing into one of the sideopenings will pass into the de flector, and no turbulence can occur between the deflectorand the chimney wall which would blow downthe chimney or disturb smooth upward flow The depth of the deflectori not, particularly critical, but thejimportant consideration'is that 7 it be sufliciently shallow so that the air will not be deflected from a horizontal course any more than air should have asufiicient upward component to create agood draft by aspirating action. It is particularly important that the area of opening between the floor of the deflector and the cover 2 be sufficiently large that the flow is not restricted. Also when the air strikes either the cover or the deflector it should not be driven into a pocket, but rather always be directed generally onwthrough the passage; Thus the bottom of the truncated deflector should be of substantial area and of fairly uniform dimensions in all directions, preferably being about one-third ofthe internal width of the chimney. The-depth of the deflector may be somewhat greater, being perhaps 40% of the internal chimney width. Thus although the transverse air passage contracts in lateral extent toward the center of the chimney because of the convergence ofthe partitions its vertical extent'increases despite the downward curvature of surfaces 22 onthe cover. The outer edge, of the cover, the lower edge of an opening I 0,.andthe lower corner of the deflector between its'bottom and opposite side wall will be generally in line if such dimensions are used, and aligned with'the. intermediate deflector edge.

-In'operation, although the partitions are fixed, wind will blow into at least one and not more than two of such openings in a rectangular chimney structure, and will flow out through the opening or openings on the opposite side of the chimney; .Thus air may blow somewhat downwardinto an opening [0 in one side of the chimney directly into the deflector, which, by impact against its opposite, upwardlyinclined side, will divert the air'for flow out through the opening on the opposite sideof the chimney. (Drdinarily, however, thewind will blow more nearly horizontally into the opening, and be guided downward into the deflector by striking one of the curved surfaces 22. Thecurvature of these surfaces is considerably less than a quadrant, so that air is not diverted directly downward. Turbulent action in a pocket at the bottom of the deflector is thus avoided, for at most the air will strike the floor of the truncated deflector at an acut angle, to flowalong it and up the opposite. side of the deflector, and thence out through the opposite.

force incoming air to flow down the chimney instead of through the transverse passage between the deflector and the cover. On the other hand, the flow of air emerging from the deflector will produce a strong aspirating action upon the comof said deflector sides being spaced slightly in? bustion gases and smoke rising through the chimney, to draw them outward through the discharge opening ID with the air. It is thu unnecessary for thesmoke passage betweenthe upper edg of, the deflector and the inner chimney, wall to be as 1. In combination, a chimney having openings 7 in its opposite sides near the topthereof, a cover member closing the top of said chimney, a hollow truncated pyramidal deflector having a bottom of substantial area and sides flaringupwardly and outwardly from said bottom, the upper edges wardly from the inner walls of' said chimney to afford a smoke passage therebetween, and being disposed below the lower edges orthe side openings in said chimney a distance less than the spacing of such edges from the. chimney walls, and partition means fixed within said chimney in a position interposed between such opposite side openings and extending from said cover member downward into said deflector slightly be low the upper edges of its sides.

In combination, a chimney closed at its top and laterallyopen on all sides adjacent its top, partition means 'flxed within said chimney centrally thereof and extending from its closed top downward completely through and to a level below its laterally open portion, a hollow truncated pyramidal deflector having a bottom disposed well below said partition means and of a width equal to at least substantially one-third the corresponding width of the flue passage and sides flaring upwardly and outwardly from its bottom, the edges of said deflector sides being spaced slightly inwardly from the inner walls of said chimney to afford a smoke passage therebetween, and being disposed below the lower edges of the side openings in said chimney a distance less than the spacing of such edges from the chimney walls but above'the lower edge of said partition means.

3. In combination, a chimney having openings in its opposite sides near the top thereof, a cover member closing the top of said chimney, a hollow truncated pyramidal deflector having a flat bottom of substantial area and sides flaring upwardly and outwardly from saidbottom, the upper'edges of said deflector sides being spacedslightly inwardly from the inner walls of saidchimney to afford a smoke passage therebetween, and being disposed below the lower edges of the side openings in said chimney a distance less than the spacing of such edges from ,the chimney walls,

, fixed partition means within said body interposed between such opposite side openings and extend-- ing from said cover member downward into said 1 cover, the height of such a chimney opening, the

deflector slightly below the upper edges of its sides, said cover member defining a curved surface at one side of said partition means to deflect downward into said deflector air entering one such side opening, and further defining acurved surface at the other side of said partition means for guiding outward through the other side opening air emerging from beneath said partition means and flowing out of said deflector.

4. In combination, a rectangular chimney having an opening in each side thereof near its top, a cover member closing the top of said chimney, a hollow truncated pyramidal deflector having a rectangular bottom of a width equal to substantially one-third the corresponding width of the flue passage, and sides flaring upwardly and outwardly from such bottom, the depth of such deflector being slightly greater than the minimum width of the bottom, the upper side edges of said deflector being parallel to and spaced inwardly from the corresponding adjacent inner walls of said chimney, to afiord a smoke passage therebetween, and being disposed below the lower edges of said lateral openings 2. distance less than the spacing from such walls, and two intersecting fixed imperforate partitions disposed diagonally of said chimney, extending from said cover member downward to a level slightly below the upper edges of said deflector sides.

5. In combination, a rectangular chimney having openings in its opposite sides near the top thereof, a cover member closing the top of said chimney and projecting laterally beyond the sides thereof, a hollow truncated pyramidal deflector having a flat rectangular bottom of substantial'area and sides flaring upwardly and outwardly from said bottom, the projection of said 6. In combination, a rectangular chimney having openings in its opposite sides near the top thereof, a cover member closing the top of said chimney and projecting laterally beyond the sides thereof, a hollow truncated pyramidal deflector having a flat rectangular bottom of substantial area and sides flaring upwardly and outwardly from said bottom; the projection of said cover, the height of such a chimney opening, the depth of said deflector, and the width of its bottom being such that a marginal edge of the cover, the lower edge of the adjacent chimney opening, the upper edge of the deflector side adjacent to such opening, and the corner between the deflector bottom and its inclined side opposite such cover edge are disposed in substantially linear relationship, the upper edges of said deflector being spaced from the adjacent inner walls of the chimney to afford a smoke passage therebetween, and imperforate partition means fixed within said chimney in a position interposed between such opposite side openings and extending from said cover member downward into such deflector slightly below the upper edges of its sides.

EMIIL ZIMMERMAN. 

